Add settings tooltips and search to the web UI

Help users quickly find settings and understand how each one works.

Tooltips: a new delegated controller (static/v3/js/tooltips.js) drives an
accessible (i) info tooltip that appears on hover, keyboard focus, and tap.
A shared `help_tip` Jinja macro (partials/_macros.html) emits the trigger;
the plugin config macro and the core settings partials now surface help
text through it. Per the design, the always-visible field help paragraphs
are folded into the tooltip to declutter the forms, and the hardware/display
settings carry authored detail (default, range, recommendation).

Search: a global header search box finds settings across every settings tab
— even ones not yet opened — via a lazy client-side index built by scanning
the same field markup (static/v3/js/settings-search.js). Selecting a result
switches tabs, waits for the field to load, then scrolls to and flashes it.
A per-tab filter box hides non-matching fields on the current tab.

Plugin settings get tooltips for free by reusing each field's schema
`description`; every settings field also gets a stable `setting-<tab>-<key>`
anchor id for search navigation.

Styling uses the existing --color-* theme vars so light/dark mode both work,
and honors prefers-reduced-motion. Adds Flask render smoke tests that assert
each settings partial ships tooltips, anchors, and a filter box.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_014gZxznuxw8L92FUMBN3Nqz

web_interface/templates/v3/partials/durations.html

@@ -1,9 +1,12 @@
+{% import 'v3/partials/_macros.html' as ui %}
 <div class="bg-white rounded-lg shadow p-6">
     <div class="border-b border-gray-200 pb-4 mb-6">
         <h2 class="text-lg font-semibold text-gray-900">Display Durations</h2>
         <p class="mt-1 text-sm text-gray-600">Configure how long each screen is shown before switching. Values in seconds.</p>
     </div>
 
+    {{ ui.settings_filter() }}
+
     <form hx-post="/api/v3/config/main"
           hx-ext="json-enc"
           hx-headers='{"Content-Type": "application/json"}'
@@ -15,9 +18,9 @@
 
         <div class="grid grid-cols-1 md:grid-cols-2 lg:grid-cols-3 gap-4">
             {% for key, value in main_config.display.display_durations.items() %}
-            <div class="form-group">
+            <div class="form-group" id="setting-durations-{{ key }}" data-setting-key="display.display_durations.{{ key }}">
                 <label for="duration_{{ key }}" class="block text-sm font-medium text-gray-700">
-                    {{ key | replace('_', ' ') | title }}
+                    {{ key | replace('_', ' ') | title }}{{ ui.help_tip('How long the ' ~ (key | replace('_', ' ')) ~ ' screen stays on before rotating to the next one, in seconds.\nRange: 5–600. Currently ' ~ value ~ 's.', key | replace('_', ' ') | title) }}
                 </label>
                 <input type="number"
                        id="duration_{{ key }}"
@@ -26,7 +29,6 @@
                        min="5"
                        max="600"
                        class="form-control">
-                <p class="mt-1 text-sm text-gray-600">{{ value }} seconds</p>
             </div>
             {% endfor %}
         </div>